Hardness Testing

TPS performs hardness testing services, useful in determining mechanical characteristics of metals, alloys, and other materials. Hardness testing provides economical and efficient quality verifications of raw and manufactured materials. All hardness testing machines at TPS are calibrated to meet the A2LA’s ISO 17025 standards, to ensure accurate results.

Rockwell Hardness

The most commonly used metal hardness scale is Rockwell; TPS routinely tests on the HRB and HRC scales, as well as HRN and HRT superficial scales. Testing on other scales is available. ASTM A370 provides a tensile strength approximation based on hardness reading. Indentation diameter is roughly 1/16”, so the test is can be considered nondestructive. Related Standard: ASTM E18.


TPS performs Vickers and Knoop microhardness tests with indentation loads ranging from 10g to 1kg. Microhardness is beneficial when samples are too small for Rockwell or Brinell testing. This test can also be used to characterize case hardening properties, carburization depth, secondary phase particles, and weld profiles (weld metal, heat affected zone, and base metal). TPS’s reports include microhardness values, which can be converted to Rockwell or Brinell scales. Values can also be used to approximate tensile strength. TPS mounts and polishes samples to a metallographic finish. Microhardness testing is a destructive test. Related Standard: ASTM E384

Brinell Hardness

TPS also performs Brinell Hardness, which is similar to Rockwell, but employs different indenters and applied loads. Brinell Hardness testing is typically considered destructive. Brinell readings can be converted to Rockwell scale, and used to approximate tensile strength. Related Standard: ASTM E10